The Wii U isn't doing well. "We're told by someone with access to the NPD's data that sales for January were 'well under' 100,000 units. By our estimates, sales were somewhere between 45,000 and 59,000 units for the month, which is lower than any of the three previous-generation home consoles sold in their worst months, with the possible exception of a recent performance by the original Wii." All that is old will be new again.

I think there's a myth about Wii game sales, they were not bad at all (in fact it was 1st in # of games sold too, 800 millon games!)

Wii had a tie ratio similar to Xbox 360 and even higher than PS3 during the first years. Yeah, it declined very deeply in the last years but that's because Nintendo abandoned Wii to concentrate efforts on 3DS.

As I said before, I think people buy Nintendo consoles mainly to play Nintendo games and the luck of their consoles depends totally on Zelda, Mario and company.